Background/Purpose: Multiplex assays that measure anti-nuclear autoantibodies (ANA) in real time using whole blood were developed on the Maverick(TM) instrument (Genalyte, Inc., USA). Because the assay takes less than 10 minutes to complete, it would be possible to perform the test in a near patient setting in an outpatient clinic. The purpose of this study was to evaluate the feasibility of using this novel instrument to perform ANA 8 tests in the clinic and to compare those results to the same sample tested in Genalyte’s CLIA registered laboratory.

Methods: An Institutional Review Board (IRB) application was approved so that patients who were seeing a rheumatologist and were going to be tested for ANA using the clinics’ standard lab testing procedures could also volunteer to donate additional venous and/or finger-stick blood for further testing. Both the venous and finger-stick blood were immediately tested on the ANA 8 on the Maverick instrument in the clinic. This multiplex immunoassay measures autoantibodies to SS-A 60, SS-B, Sm, Sm/RNP, Scl-70, Jo-1, centromere B and dsDNA. The cutoff between negative and positive was standardized so that 40 AU and greater are positive. Even though results were available in real time, the protocol specified that the doctor would not be given results until the end of the study. 154 samples of venous blood were collected, tested on the Maverick and then returned to the Genalyte CLIA lab for processing into serum for comparison testing on the FIDIS Connective 10 (Theradiag, France). In addition, 54 samples of finger-stick blood were also collected for comparison testing.

Results: The results between whole blood finger stick (WBFS) and whole blood venous (WBVN) tested on the Maverick, and serum tested on the FIDIS for positive, negative and total agreement are shown in the table below.

  The r² correlation between the values for all of the 8 ANA markers from finger stick (54 times 8 yields 432 results) versus venous whole blood is 0.98 as shown below.

Conclusion: This pilot study demonstrated the feasibility of performing multiplex ANA testing on whole blood in a near patient setting in an outpatient clinic.  There is extremely high correlation for absolute value between venous blood and finger-stick blood, and between positive and negative results seen with whole blood on the Maverick and serum on the FIDIS.  While further studies are required to quantify the impact such a diagnostic system might have on quality of care, there is potential for such a capability to improve timeliness of diagnosis, increase patient centricity and reduce overall healthcare resource utilization.